package com.tool.code;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

/**
 * 验证码：有干扰线
 */
@WebServlet("/checkCodeServlet1")
public class CheckCodeServlet1 extends HttpServlet {

    public void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        int width = 100;
        int height = 50;
        //创建一对象，在内存中图片（验证码图片对象）
        BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
        //美化图片
        //画背景色
        Graphics g = image.getGraphics();
        g.setColor(Color.pink);
        g.fillRect(0,0,width,height);
        //画边框
        g.setColor(Color.blue);
        g.drawRect(0,0,width-1,height-1);

        String str = "QWERTYUIOPASDFGHJKLZXCVBNMqwertyuiopasdfghjklzxcvbnm0123456789";
        //生成随机4个验证码
        Random ran = new Random();
        StringBuffer sb = new StringBuffer();
        for (int i = 1; i <= 4; i++) {
            int index = ran.nextInt(str.length());//随机数字0~str.length()
            char ch = str.charAt(index);//str中一个字符
            sb.append(ch);
            //写验证码
            g.drawString(ch+"",width/5*i,25);
        }
        String checkCode_session = sb.toString();
        //将验证码存入session
        req.getSession().setAttribute("checkCode_session",checkCode_session);

        //干扰线
        g.setColor(Color.green);
        for (int i = 0; i < 10; i++) {
            int x1 = ran.nextInt(width);
            int x2 = ran.nextInt(width);

            int y1 = ran.nextInt(height);
            int y2 = ran.nextInt(height);
            g.drawLine(x1,y1,x2,y2);
        }
        //将图片输出到页面展示
        ImageIO.write(image,"jpg",resp.getOutputStream());
    }

    public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doPost(req, resp);
    }
}
